Wednesday, August 13, 2014

That's a relief.

So, I got an email flyer from Tactical Defense Solutions, a company with whom I'd dealt before, announcing that they had some Sumbro 9mm ammunition in stock for $12 per 50rd box. I needed some 9mm blasting ammo and twelve bucks was as cheap as I'd seen brass-cased reloadable pistol chow in a while, and so I ordered some.

Like many people, after placing my order for something, I then went to Google to validate my decision. This was the first thing I found:

"Well, that's just festive," I thought. Although the stuff I ordered was 124gr, and the ad specifically stated that it had soft commercial primers, so maybe it wasn't suspect?

I took some to the range today and chrono'ed a ten-shot string...

Hot Or Not?

1104 feet-per-second average out of a full-size M&P for 124gr 9x19 is not hot at all, and the primers all looked normal, with no flattening or cratering. The lot number/mfg. date stamped on the inside of the box flaps is "02-14-2014".

MAYBE YOU SHOULD SPECIFY THE LOT NUMBER IN YOUR THREAD TITLE, UZITALK DUDE, AND NOT PANIC PEOPLE. THANK YOU!

It's not my intent to be fulsome, but your posts are the sort that I wish more people would write. In this case, you provide some actual data, not just a "It kicked harder than I'm used to" or "Dude! This stuff ROCKS!"

Ditto your ongoing posts about the PPX: you provide round count, photos to show wear (or lack thereof) and some thoughtful remarks about accuracy and performance.

One of the problems I encountered with 9mm/.38 caliber guns is the range of bore sizes. Ideally, the bore diameter of the 9mm is 0.354 plus or minus a few thousandths while the .38/.357 is supposed to be 0.357. In practice, I've seen bore diameters ranging from 0.350 to 0.370.

A high pressure load developed in a Browning Hi-Power with a bore diameter of 0.358 will be dangerously high when loaded into a S&W with a 0.352 bore.

Something that manufacturers seldom discuss is that they use one set of bore tools for all their 9mm/.38 caliber guns. In the past, Smith would measure 0.354 while Colt 9mm barrels would measure 0.357. The rationale is cost savings; the two calibers are close enough to allow one set of bore tools.

In any case, you need to understand how these affect your gun and ammunition.

There was a huge amount (several pallets) of Sumbro 9mm at Knob Creek during the last shoot that was being blown out cheap as "+P+ sub-gun only" ammo. The seller had a copy of the HP White pressure test (including lot number) that went along with each purchase. I picked up one of the sheets for reference and so I will have to find it if anyone is curious about the exact number, but I know it was above 38,500 PSI. The boxes I examined said the ammo was made in Macedonia.